MR imaging system with interactive MR geometry prescription control

ABSTRACT

A magnetic resonance (MR) imaging system equipped with real-time imaging capability and methods of interactively prescribing geometry to excitation profiles of structure of interest, are disclosed herein. The MR imaging system includes a graphical user interface for displaying and receiving prescription commands, a display screen for displaying MR images and the graphical user interface, and an input device for inputting prescription commands. The MR imaging system allows an operator to prescribe the boundary geometry of a subsequent imaging volume and to rapidly view the prescribed boundary imaging sections prior to committing to the subsequent imaging volume acquisition. The MR imaging system also allows the operator to retrieve boundary geometry of a previously prescribed imaging volume and to rapidly view the imaging sections corresponding to the retrieved boundary geometry prior to initiating the image volume acquisition.

FIELD OF THE INVENTION

[0001] The present invention relates generally to magnetic resonance(MR) imaging systems and methods. More particularly, the presentinvention relates to a MR imaging system equipped for real-time imagingand methods for assisting the operator to interactively prescribe thegeometry of the excitation profile of a structure of interest forsubsequent acquisition of a MR image of the structure of interest.

BACKGROUND OF THE INVENTION

[0002] When a substance such as human tissue is subjected to a uniformmagnetic field (polarizing field Bo), the individual magnetic moments ofthe spins in the tissue attempt to align with this polarizing field, butprocess about it in random order at their characteristic Larmorfrequency. If the substance, or tissue, is subjected to a magnetic field(excitation field B₁) which is the x-y plane and which is near theLarmor frequency, the net aligned moment, M_(z), may be rotated, or“tipped”, into the x-y plane to produce a net transverse magnetic momentM. A signal is emitted by the excited spins after the excitation signalB₁ is terminated and this signal may be received and processed to forman image.

[0003] When utilizing these signals to produce images, magnetic fieldgradients (G_(x), G_(y) and G_(z)) are employed. Typically, the regionto be imaged is scanned by a sequence of measurement cycles in whichthese gradients vary according to the particular localization methodbeing used. The resulting set of received NMR signals are digitized andprocessed to reconstruct the image using one of many well knownreconstruction techniques.

[0004] When attempting to define the volume of coverage of an MR imagingscan, the NMR system operator may desire to quickly view a preview MRimage (such as a real-time MR image) of the anatomical section withinthis volume of coverage. This process can be particularly useful whenprescribing a three dimensional imaging volume, in which the desiredhigh spatial resolution requires the thinnest slab possible. It isdesirable to position this thin slab such that the anatomical sectionwithin the volume of coverage is complete, i.e. for example, covers theentire desired vascular network. Thus, a quick view of each side of theslab prior to initiating the three dimensional acquisition is useful forinsuring that the entire anatomical section desired is within thedefined volume of coverage.

[0005] Typically, two dimensional axial, sagittal and coronal “scout”images are first acquired. Such scout images are stored for later use.To use, the operator calls up the scout image and either graphically orexplicitly (using geometry coordinates) prescribes the imaging volumedirectly on the scout images. The imaging volume may be either a twodimensional stack of slices or a three dimensional slab of the structureof interest. The drawback of this technique is that the operator doesnot actually see the results of the prescribed geometry until thesubsequent imaging volume is acquired. Prescription errors cannot bedetected nor corrected until the imaging volume acquisition is complete.Thus, when prescription errors exist, the operator is required tore-prescribe and re-acquire the imaging volume of the desired anatomicalsection.

SUMMARY OF THE INVENTION

[0006] One embodiment of the invention relates to an MR imaging systemhaving interactive MR geometry prescription control. The MR imagingsystem provides a method for prescribing geometry to a subsequentimaging volume of a structure of interest. The operator interactivelyacquires and displays a first real-time imaging section using an inputdevice. Using the input device, the operator sets the first geometryinformation defining the scan plane corresponding to the first real-timeimaging section in a buffer of the MR imaging system. The first geometryinformation prescribes the “start” boundary geometry of the subsequentimaging volume. Next, the operator interactively acquires and displays asecond real-time imaging section using the input device. Similarly, theoperator sets the second geometry information defining the scan planecorresponding to the second real-time imaging volume in the buffer ofthe MR imaging system. The second geometry information prescribes the“end” boundary geometry of the subsequent imaging volume. Henceforth,the boundary geometry defining the desired subsequent imaging volume,contain within it the desired structure of interest such as a vascularnetwork, can be efficiently and rapidly checked and prescribed prior toinitiating acquisition of the desired imaging volume.

[0007] Another embodiment of the invention relates to retrievinggeometry information of a previously prescribed imaging volume. Usingthe input device, the operator selects a previously prescribed imagingvolume and the system loads the “start” and “end” boundary geometryinformation corresponding to the selected previously prescribed imagingvolume into the buffer. The operator can then acquire and displayreal-time imaging sections using the “start” and “end” boundary geometryinformation retrieved from the previously prescribed imaging volume. Theoperator typically uses a graphical user interface in conjunction withthe input device and a display screen for interactively prescribing theMR geometry of excitation profiles of structures of interest.

[0008] It is an object of the present invention to provide a featurewhich allows the operator to utilize the speed of real-time imagingsection acquisition and display thereof to accurately and efficientlyprescribe the desired imaging volume boundary geometry prior tocommitting to the imaging volume acquisition. Another object of thepresent invention is to allow the operator to retrieve boundary geometrypreviously prescribed for an imaging volume, to rapidly view imagingsections corresponding to the retrieved boundary geometry, and to modifythe boundary geometry, if necessary, prior to committing to the imagevolume acquisition.

[0009] Other principal features and advantages of the present inventionwill become apparent to those skilled in the art upon review of thefollowing drawings, the detailed description and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The invention will become more fully understood from thefollowing detailed description, taken in conjunction with theaccompanying drawings, wherein like reference numerals refer to likeparts, in which:

[0011]FIG. 1 is a block diagram of a MR imaging system which employs thepresent invention;

[0012]FIG. 2 is an electrical block diagram of the transceiver whichforms part of the MR imaging system of FIG. 1; and

[0013]FIG. 3 is an illustration of the graphical user interface on thedisplay screen of the operator console of the MR imaging system of FIG.1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Referring first to FIG. 1, there is shown the major components ofa preferred MR imaging system which incorporates the present invention.The operation of the system is controlled from an operator console 100which includes an input device 101, a control panel 102 and a display104. The console 100 communicates through a link 116 with a separatecomputer system 107 that enables an operator to control the productionand display of images on the display 104. The computer system 107includes a number of modules which communicate with each other through abackplane. These include an image processor module 106, a CPU module 108and a memory module 113, known in the art as a frame buffer for storingimage data arrays. The computer system 107 is linked to a disk storage111 and a tape drive 112 for storage of image data and programs, and itcommunicates with a separate system control 122 through a high speedserial link 115.

[0015] The system control 122 includes a set of modules connectedtogether by a backplane. These include a CPU module 119 and a pulsegenerator module 121 which connects to the operator console 100 througha serial link 125. It is through this link 125 that the system control122 receives commands from the operator which indicate the scan sequencethat is to be performed. The pulse generator module 121 operates thesystem components to carry out the desired scan sequence. It producesdata which indicates the timing, strength and shape of the RF pulseswhich are to be produced, and the timing of and length of the dataacquisition window. The pulse generator module 121 connects to a set ofgradient amplifiers 127, to indicate the timing and shape of thegradient pulses to be produced during the scan. The pulse generatormodule 121 also receives patient data from a physiological acquisitioncontroller 129 that receives signals from a number of different sensorsconnected to the patient, such as ECG signals from electrodes orrespiratory signals from a bellows. And finally, the pulse generatormodule 121 connects to a scan room interface circuit 133 which receivessignals from various sensors associated with the condition of thepatient and the magnet system. It is also through the scan roominterface circuit 133 that a patient positioning system 134 receivescommands to move the patient to the desired position for the scan.

[0016] The gradient waveforms produced by the pulse generator module 121are applied to a gradient amplifier system 127 comprised of G_(x), G_(y)and G_(z) amplifiers. Each gradient amplifier excites a correspondinggradient coil in an assembly generally designated 139 to produce themagnetic field gradients used for position encoding acquired signals.The gradient coil assembly 139 forms part of a magnet assembly 141 whichincludes a polarizing magnet 140 and a whole-body RF coil 152.

[0017] A transceiver module 150 in the system control 122 producespulses which are amplified by an RF amplifier 151 and coupled to the RFcoil 152 by a transmit/receiver switch 154. The resulting signalsradiated by the excited nuclei in the patient may be sensed by the sameRF coil 152 and coupled through the transmit/receive switch 154 to apreamplifier 153. The amplified NMR signals are demodulated, filtered,and digitized in the receiver section of the transceiver 150. Thetransmit/receive switch 154 is controlled by a signal from the pulsegenerator module 121 to electrically connect the RF amplifier 151 to thecoil 152 during the transmit mode and to connect the preamplifier 153during the receive mode. The transmit/receive switch 154 also enables aseparate RF coil (for example, a head coil or surface coil) to be usedin either the transmit or receive mode.

[0018] The NMR signals picked up by the RF coil 152 are digitized by thetransceiver module 150 and transferred to a memory module 160 in thesystem control 122. When the scan is completed and an entire array ofdata has been acquired in the memory module 160, an array processor 161operates to Fourier transform the data into an array of image data. Thisimage data is conveyed through the serial link 115 to the computersystem 107 where it is stored in the disk memory 111. In response tocommands received from the operator console 100, this image data may bearchived on the tape drive 112, or it may be further processed by theimage processor 106 and conveyed to the operator console 100 andpresented on the display 104.

[0019] Referring particularly to FIGS. 1 and 2, the transceiver 150produces the RF excitation field B₁ through power amplifier 151 at acoil 152A and receives the resulting signal induced in a coil 152B. Asindicated above, the coils 152A and B may be separate as shown in FIG.2, or they may be a single wholebody coil as shown in FIG. 1. The base,or carrier, frequency of the RF excitation field is produced undercontrol of a frequency synthesizer 200 which receives a set of digitalsignals (CF) from the CPU module 119 and pulse generator module 121.These digital signals indicate the frequency and phase of the RF carriersignal produced at an output 201. The commanded RF carrier is applied toa modulator and up converter 202 where its amplitude is modulated inresponse to a signal R(t) also received from the pulse generator module121. The signal R(t) defines the envelope of the RF excitation pulse tobe produced and is produced in the module 121 by sequentially readingout a series of stored digital values. These stored digital values may,in turn, be changed from the operator console 100 to enable any desiredRF pulse envelope to be produced.

[0020] The magnitude of the RF excitation pulse produced at output 205is attenuated by an exciter attenuator circuit 206 which receives adigital command, TA, from the backplane 118. The attenuated RFexcitation pulses are applied to the power amplifier 151 that drives theRF coil 152A. For a more detailed description of this portion of thetransceiver 122, reference is made to U.S. Pat. No. 4,952,877 which isincorporated herein by reference.

[0021] Referring still to FIGS. 1 and 2 the NMR signal produced by thesubject is picked up by the receiver coil 152B and applied through thepreamplifier 153 to the input of a receiver attenuator 207. The receiverattenuator 207 further amplifies the signal by an amount determined by adigital attenuation signal (RA) received from the backplane 118.

[0022] The received signal is at or around the Larmor frequency, andthis high frequency signal is down converted in a two step process by adown converter 208 which first mixes the NMR signal with the carriersignal on line 201 and then mixes the resulting difference signal withthe 2.5 MHz reference signal on line 204. The down converted NMR signalis applied to the input of an analog-to-digital (A/D) converter 209which samples and digitizes the analog signal and applies it to adigital detector and signal processor 210 which produces 16 bit in-phase(I) values and 16-bit quadrature (Q) values corresponding to thereceived signal. The resulting stream of digitized I and Q values of thereceived signal are output through backplane 118 to the memory module160 where they are normalized in accordance with the present inventionand then employed to reconstruct an image.

[0023] The 2.5 MHz reference signal as well as the 250 kHz samplingsignal and the 5, 10 and 60 MHz reference signals are produced by areference frequency generator 203 from a common 20 MHz master clocksignal. For a more detailed description of the receiver, reference ismade to U.S. Pat. No. 4,992,736 which is incorporated herein byreference.

[0024] In one embodiment of the present invention, an operatorinteractively prescribes geometry to define a subsequent MR imagingvolume or receives geometry information from a previously defined MRimaging volume of the structure of interest, such as an anatomicalstructure. Such interactive geometry prescription is accomplished fromthe operator console 100 (also referred to as an operator interface)using the input device 101. The input device 101 is selected from agroup including, but not limited to, a mouse, a joystick, a keyboard, atrack ball, a touch screen, a light wand, and a voice control. The MRimaging system of the present invention is capable of imaging in anydesired orientation within the structure of interest and is equipped toperform both real-time acquisitions and non real-time acquisitions. Inparticular, real-time refers to continuous acquisition andreconstruction of MR image data as rapidly as it is acquired. Areal-time MR image can be acquired and displayed in approximately onesecond or less, as constrained by MR imaging system performance.

[0025]FIG. 3 shows a graphical user interface 105 used in an embodimentof the present invention. The graphical user interface 105 and the MRimage of the structure of interest is displayed on the display 104 (alsoreferred to as an electronic display) of the MR imaging system. Theoperator interacts with the graphical user interface 105 using the inputdevice 101. The graphical user interface 105 includes a set startboundary icon 10, a three-point start boundary geometry icon 12, a setend boundary icon 14, and a three-point end boundary geometry icon 16.The three-point start and end boundary geometry icons 12, 16,respectively, each contain geometry coordinates defining the location ofa planar section of the structure of interest in the imaging volume.These coordinates are defined in the patient right-left direction (R/L),patient anterior-posterior direction (A/P), and patientsuperior-inferior direction (S/I), hereafter referred to as center pointRAS coordinates. The graphical user interface 105 also includes anacquire start boundary icon 18, an acquire end boundary icon 20, anapply location icon 22, a retrieve location icon 24, and a save seriesicon 26.

[0026] First, to prescribe the boundary geometry of a subsequent orproposed imaging volume, it is desirable for the operator to viewreal-time imaging sections, preferably two dimensional planar sections,corresponding to the boundaries defining the desired subsequent imagingvolume prior to committing to those imaging sections as the boundariesof the subsequent imaging volume. Typically the operator maneuvers theMR imaging system to acquire and display a real-time imaging section ondisplay 104 directed to the structure of interest that defines oneboundary of the desired subsequent imaging volume. The operator thenregisters this real-time imaging section as one boundary plane of thesubsequent imaging volume by “clicking” on the set start boundary icon10 on the graphical user interface 105. A geometry representation of thescan plane of this imaging section is determined and stored (i.e. in atext buffer) as text in center point RAS coordinates. The geometryrepresentation of the start boundary is also displayed in thethree-point start boundary geometry icon 12 of the graphical userinterface 105.

[0027] Next, the operator manipulates the MR imaging system to acquireand display another real-time imaging section on display 104 directed tothe structure of interest that defines another boundary of the desiredsubsequent imaging volume. The operator registers this current real-timeimaging section as another boundary plane of the subsequent imagingvolume by clicking on the set end boundary icon 14 on the graphical userinterface 105. Similar to above, a geometry representation of the scanplane of this current imaging section is determined, stored, anddisplayed in center point RAS coordinates in the three-point endboundary geometry icon 16 of the graphical user interface 105.

[0028] It should be understood that non real-time imaging sections canalso be utilized to set the start and end boundaries. The advantage ofthe real-time imaging sections is that the operator can very rapidlyview multiple imaging sections of interest for the purposes ofprescribing the subsequent imaging volume. Additionally, the operatorcan repeatedly set the start and/or end boundary planes by acquiring anddisplaying a new imaging section and then clicking on the set startboundary icon 10 or the set end boundary icon 14, as desired. In thisway, the present embodiment provides the operator with a finer degree ofgeometry prescription control.

[0029] The remaining boundary geometry defining the subsequent imagingvolume can be identical to the corresponding boundaries of the currentreal-time imaging section, i.e., the in-plane field of view.Alternatively, the remaining boundary geometry can be definedindependently with additional icons on the graphical user interface 105using the input device 101 (not shown in FIG. 3). Still further, in thecase where the two boundary planes are not parallel to each other, theMR imaging system can apply a best fit algorithm, or other suitablealgorithms, to the start and end boundaries to calculate the remainingboundary geometry.

[0030] The operator can now click on the apply location icon 22, whichtransfers the start and end boundary geometry information contained inicons 12, 16 to the subsequent imaging volume. Once the start and endboundary geometry information has been applied, the operator can clickon the save series icon 26. This signals the MR imaging system to checkfor a complete boundary geometry prescription and prepares the systemfor acquisition of the prescribed imaging volume.

[0031] Second, to retrieve the boundary geometry of a previouslyprescribed or defined imaging volume and to utilize the retrievedgeometry information to check the prescribed boundary geometry or to useit as a starting point from which to prescribe a subsequent imagingvolume, the operator starts by selecting a previously prescribed imagingvolume from a list or display of one or more previously prescribedimaging volumes on display 104 (not shown in FIG. 3). The previouslyprescribed imaging volumes can be, but is not limited to, previouslystored real-time acquisitions, previously stored non real-timeacquisitions, or previously stored graphically or explicitly (usinggeometry coordinates) prescribed imaging volumes from scout images. Thenthe operator clicks on the retrieve location icon 24 to load boundarygeometry information, in center point RAS coordinates, into the bufferscorresponding to icons 12, 16. Icons 12, 16 displays the two boundaryplane geometry information.

[0032] Using the acquire start boundary icon 18 or the acquire endboundary icon 20, the operator commands the MR imaging system to acquireand display a real-time imaging section, typically a two-dimensionalplaner section, defined by the retrieved geometry information in thethree-point start boundary geometry icon 12 or the three-point endboundary geometry icon 16, respectively. Alternatively, the retrievedgeometry information can be used to acquire and display a non real-timeimaging section. The feature embodied in the acquire start and endboundary icons 18, 20 are particularly useful for checking or previewingthe boundaries of a previously prescribed imaging volume that has notbeen acquired, such as an imaging volume prescribed using scout images.

[0033] In another embodiment of the present invention, the imagingsection acquired and displayed as a result of clicking the acquire startor end boundary icon 18, 20 can be modified such that an acquisition ofa new imaging section occurs and the said section is displayed(replacing the current imaging section displayed). The modification, forexample, can be accomplished by graphically or explicitly (usinggeometry coordinates) changing the scan plane of the currently imagingsection. This new imaging section, in turn, can be utilized to replacethe retrieved geometry information stored in icon 12 or 16 by clickingon the set start or end boundary icon 10 or 14, respectively. Thus, inthis manner, the geometry information of a previously prescribed imagingvolume can be used as a starting point from which to prescribe asubsequent imaging volume or to refine the prescription of a previouslyprescribed imaging volume.

[0034] It should be apparent that there has been provided in accordancewith one embodiment of the present invention a method for accurately andefficiently prescribing the geometry of a subsequent imaging volume of astructure of interest using at least two two-dimensional MR imagingsections. Moreover, an embodiment of the present invention also providesa method for retrieving geometry information from a previouslyprescribed imaging volume and manipulating this geometry information.While the embodiments illustrated in the FIGS. and described above arepresently preferred, it should be understood that these embodiments areoffered by way of example only. For example, setting the start or endboundary described herein may be accomplished directly by inputtinggeometry coordinates rather than by displaying an imaging section andextracting or determining geometry coordinates therefrom. Accordingly,the invention is not limited to a particular embodiment, but extends toalternatives, modifications, and variations that nevertheless fallwithin the spirit and scope of the appended claims.

What is claimed is:
 1. A method for prescribing geometry of an imagingvolume of a structure of interest positioned in a magnetic resonance(MR) imaging system, comprising: a) selecting a first boundary plane ofthe structure of interest, wherein the first boundary plane isprescribed by a first imaging section of the structure of interest; b)determining a first geometry information corresponding to the firstimaging section of the structure of interest; c) storing the firstgeometry information in the MR imaging system; d) selecting a secondboundary plane of the structure of interest, wherein the second boundaryplane is prescribed by a first imaging section of the structure ofinterest; e) determining the second geometry information correspondingto the second imaging section of the structure of interest; f) storingthe second geometry information in the MR imaging system; and g)applying the first and second geometry information of the first andsecond imaging sections, respectively, to prescribe a boundary geometrydefining a subsequent imaging volume of the structure of interest. 2.The method of claim 1, further comprising displaying the first andsecond imaging sections of the structure of interest.
 3. The method ofclaim 1, further comprising displaying the first and second geometryinformation.
 4. The method of claim 1, wherein at least one of thegeometry information is defined in center point RAS coordinates.
 5. Themethod of claim 1, wherein at least one of the geometry information isstored in a text buffer.
 6. The method of claim 1, wherein thesubsequent imaging volume is a three-dimensional MR acquisition.
 7. Themethod of claim 1, wherein the subsequent imaging volume is comprised ofa stack of a plurality of two-dimensional MR acquisitions.
 8. The methodof claim 1, further comprising initiating the MR imaging system toacquire the subsequent imaging volume using the boundary geometryprescribed by the first and second geometry information.
 9. The methodof claim 8, wherein the acquired imaging volume is a MR scan selectedfrom a group including a real-time acquisition and a non real-timeacquisition.
 10. The method of claim 1, wherein at least one of theimaging section is a planar section from a group including a real-timeacquisition and a non real-time acquisition.
 11. The method of claim 1,wherein steps (a) and (d) are performed by an input device selected froma group including a mouse, a joystick, a keyboard, a trackball, a touchscreen, a light wand, and a voice control.
 12. The method of claim 1,wherein the first and second boundary planes are parallel to each other.13. The method of claim 1, wherein the remaining boundaries defining thesubsequent imaging volume is prescribed by the in-plane field of view ofat least one imaging section.
 14. The method of claim 1, whereinremaining boundaries defining the proposed imaging volume is prescribedby a best-fit algorithm applied to the first and second boundary planes.15. A method for retrieving geometry prescription of an imaging volumeof a structure of interest positioned in a magnetic resonance (MR)imaging system, comprising: a) selecting a previously prescribed imagingvolume of the structure of interest; b) determining a first and secondgeometry information representing a first and second boundary planes,respectively, of the previously prescribed imaging volume; c) loadingthe first and second geometry information representing the first andsecond boundary planes, respectively, in at least one buffer; and d)storing the first and second geometry information representing the firstand second boundary planes of the previously prescribed imaging volumein the MR imaging system.
 16. The method of claim 15, furthercomprising: e) selecting at least one of the geometry information; andf) sending the selected at least one of the geometry information to theMR imaging system such that an imaging section, corresponding to theselected geometry information, is acquired and displayed.
 17. The methodof claim 16, wherein the imaging section is a planar section acquiredfrom a group including a real-time acquisition and a non real-timeacquisition.
 18. The method of claim 16, wherein steps (a) and (e) areperformed by an input device selected from a group including a mouse, ajoystick, a keyboard, a trackball, a touch screen, a light wand, and avoice control.
 19. The method of claim 16, further comprising: g)prescribing a different imaging section of the structure of interest; h)determining a different geometry information corresponding to thedifferent imaging section of the structure of interest; and i) replacingat least one of the geometry information stored in the MR imaging systemwith the different geometry information corresponding to the differentimaging section.
 20. The method of claim 15, wherein the previouslyprescribed imaging volume is prescribed from scout images.
 21. Agraphical user interface for interactively prescribing geometry of anexcitation profile of a structure of interest positioned in a magneticresonance (MR) imaging system, comprising: a means for displaying animage of the structure of interest; a means for setting a startboundary; a means for setting an end boundary; a means for determiningand displaying a start boundary geometry information; a means fordetermining and displaying an end boundary geometry information; a meansfor sending the start and end boundary geometry information to the MRimaging system to acquire a subsequent imaging volume of the structureof interest, wherein the boundary geometry defining the subsequentimaging volume is prescribed by the start and end boundary geometryinformation; a means for retrieving a previously defined start and endboundary geometry information from a previously defined imaging volume;a means for displaying the previously defined start and end boundarygeometry information; a means for sending the previously defined startboundary geometry information to the MR imaging system to acquire anddisplay a start imaging section, wherein the boundary geometry definingthe start imaging section is obtained by the previously defined startboundary geometry information; and a means for sending the previouslyprescribed end boundary geometry information to the MR imaging system toacquire and display an end imaging section, wherein the boundarygeometry defining the end imaging section is obtained by the previouslydefined end boundary geometry information.
 22. The graphical userinterface of claim 21 further comprising means for finally preparing thesubsequent imaging volume for acquisition.
 23. The graphical userinterface of claim 21 further comprising a plurality of icons fordisplaying the available boundary geometry information.
 24. Thegraphical user interface of claim 21 wherein the means for setting, themeans for sending, and the means for retrieving are initiated by aninput device selected from a group including a mouse, a joystick, akeyboard, a trackball, a touch screen, a light wand, and a voicecontrol.
 25. A magnetic resonance (MR) imaging system for prescribinggeometry of an imaging volume of a structure of interest, comprising: a)means for selecting a first boundary plane of the structure of interest,wherein the first boundary plane is prescribed by a first imagingsection of the structure of interest; b) means for determining a firstgeometry information corresponding to the first imaging section of thestructure of interest; c) means for storing the first geometryinformation in the MR imaging system; d) means for selecting a secondboundary plane of the structure of interest, wherein the second boundaryplane is prescribed by a first imaging section of the structure ofinterest; e) means for determining the second geometry informationcorresponding to the second imaging section of the structure ofinterest; f) means for storing the second geometry information in the MRimaging system; and g) means for applying the first and second geometryinformation of the first and second imaging sections, respectively, toprescribe a boundary geometry defining a subsequent imaging volume ofthe structure of interest.
 26. The system of claim 25, furthercomprising means for displaying the first and second imaging sections ofthe structure of interest.
 27. The system of claim 25, furthercomprising means for displaying the first and second geometryinformation.
 28. The system of claim 25, wherein at least one of thegeometry information is defined in center point RAS coordinates.
 29. Thesystem of claim 25, wherein at least one of the geometry information isstored in a text buffer.
 30. The system of claim 25, wherein thesubsequent imaging volume is a three-dimensional MR acquisition.
 31. Thesystem of claim 25, wherein the subsequent imaging volume is comprisedof a stack of a plurality of two-dimensional MR acquisitions.
 32. Thesystem of claim 25, further comprising means for initiating the MRimaging system to acquire the subsequent imaging volume using theboundary geometry prescribed by the first and second geometryinformation.
 33. The system of claim 32, wherein the acquired imagingvolume is a MR scan selected from a group including a real-timeacquisition and a non real-time acquisition.
 34. The system of claim 25,wherein at least one of the imaging section is a planar section from agroup including a real-time acquisition and a non real-time acquisition.35. The system of claim 25, wherein at least one of the means forselecting are performed by an input device selected from a groupincluding a mouse, a joystick, a keyboard, a trackball, a touch screen,a light wand, and a voice control.
 36. The system of claim 25, whereinthe first and second boundary planes are parallel to each other.
 37. Thesystem of claim 25, wherein the remaining boundaries defining thesubsequent imaging volume is prescribed by the in-plane field of view ofat least one imaging section.
 38. The system of claim 25, whereinremaining boundaries defining the proposed imaging volume is prescribedby a best-fit algorithm applied to the first and second boundary planes.39. A magnetic resonance (MR) imaging system capable of retrievinggeometry prescription of an imaging volume of a structure of interest,comprising: a) means for selecting a previously prescribed imagingvolume of the structure of interest; b) means for determining a firstand second geometry information representing a first and second boundaryplanes, respectively, of the previously prescribed imaging volume; c)means for loading the first and second geometry information representingthe first and second boundary planes, respectively, in at least onebuffer; and d) means for storing the first and second geometryinformation representing the first and second boundary planes of thepreviously prescribed imaging volume in the MR imaging system.
 40. Thesystem of claim 39, further comprising: e) means for selecting at leastone of the geometry information; and f) means for sending the selectedat least one of the geometry information to the MR imaging system suchthat an imaging section, corresponding to the selected geometryinformation, is acquired and displayed.
 41. The system of claim 40,wherein the imaging section is a planar section acquired from a groupincluding a real-time acquisition and a non real-time acquisition. 42.The system of claim 40, wherein at least one of the means for selectingare performed by an input device selected from a group including amouse, a joystick, a keyboard, a trackball, a touch screen, a lightwand, and a voice control.
 43. The system of claim 40, furthercomprising: g) means for prescribing a different imaging section of thestructure of interest; h) means for determining a different geometryinformation corresponding to the different imaging section of thestructure of interest; and i) means for replacing at least one of thegeometry information stored in the MR imaging system with the differentgeometry information corresponding to the different imaging section. 44.The system of claim 39, wherein the previously prescribed imaging volumeis prescribed from scout images.
 45. A magnetic resonance (MR) imagingsystem for prescribing geometry of an imaging volume of a structure ofinterest, comprising: a MR imaging device configured to acquire andreconstruct MR data in real-time of at least one first and secondimaging section of the structure of interest in real-time and displayingat least one first and second imaging section of the structures ofinterest in real-time; an operator interface configured to transmit atleast one selection signal in response to an operator selecting a firstboundary plane of the structure of interest on the operator interface,wherein the first boundary plane is prescribed by the first imagingsection of the structure of interest, and the operator selecting asecond boundary plane of the structure of interest on the operatorinterface, wherein the second boundary plane is prescribed by the secondimaging section of the structure of interest; and a computer systemcoupled to the operator interface, wherein the computer system isconfigured to determine a first and second geometry informationcorresponding to the first and second imaging sections, respectively, ofthe structure of interest, in response to the at least one selectionsignal, and wherein the computer system is configured to store the firstand second geometry information in the MR imaging system.
 46. The systemof claim 45, wherein the operator interface includes an electronicdisplay configured to display the first and second imaging sections ofthe structure of interest.
 47. The system of claim 45, wherein theoperator interface includes an electronic display configured to displaythe first and second geometry information.
 48. The system of claim 45,wherein the subsequent imaging volume is selected from a group includinga three-dimensional MR acquisition and a stack of a plurality oftwo-dimensional MR acquisitions.
 49. The system of claim 45, furthercomprising a system control configured to receive an initiation signalfrom the operator interface to initiate the acquisition of thesubsequent imaging volume using the boundary geometry prescribed by thefirst and second geometry information.
 50. The system of claim 49,wherein the acquired imaging volume is a MR scan selected from a groupincluding a real-time acquisition and a non real-time acquisition. 51.The system of claim 45, wherein at least one of the imaging section is aplanar section from a group including a real-time acquisition and a nonreal-time acquisition.
 52. The system of claim 45, wherein the operatorinterface includes an input device selected from a group including amouse, a joystick, a keyboard, a trackball, a touch screen, a lightwand, and a voice control.
 53. The system of claim 45, wherein the firstand second boundary planes are parallel to each other.
 54. The system ofclaim 45, wherein the remaining boundaries defining the subsequentimaging volume is prescribed by the in-plane field of view of at leastone imaging section.
 55. The system of claim 45, wherein remainingboundaries defining the proposed imaging volume is prescribed by abest-fit algorithm applied to the first and second boundary planes. 56.A magnetic resonance (MR) imaging system capable of retrieving geometryprescription of an imaging volume of a structure of interest,comprising: a computer system configured to store at least onepreviously prescribed imaging volume of the structure of interest; anoperator interface coupled to the computer system, the operatorinterface configured to transmit at least one selection signal inresponse to an operator selecting the at least one previously prescribedimaging volume of the structure of interest on the operator interface;and a system control coupled to the computer system and the operatorinterface, wherein, in response to the at least one selection signalfrom the operator interface, the computer system determines a first andsecond geometry information representing a first and second boundaryplanes, respectively, of the previously prescribed imaging volume, andstores the first and second geometry information representing the firstand second boundary planes, respectively, in the system control, whereinthe operator interface includes an electronic display configured todisplay the first and second geometry information.
 57. The system ofclaim 56, wherein the operator interface is configured to receive atleast one of the geometry information from the operator and to transmitthe operator selected at least one of the geometry information via alink to the system control such that an imaging section, correspondingto the selected geometry information, is acquired and displayed.
 58. Thesystem of claim 56, wherein the operator interface includes an inputdevice selected from a group including a mouse, a joystick, a keyboard,a trackball, a touch screen, a light wand, and a voice control.
 59. Thesystem of claim 56, wherein the previously prescribed imaging volume isprescribed from scout images.